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Philae Lander
''Philae'' ( or ) was a robotic European Space Agency lander that accompanied the ''Rosetta'' spacecraft until it separated to land on comet 67P/Churyumov–Gerasimenko, ten years and eight months after departing Earth. On 12 November 2014, ''Philae'' touched down on the comet, but it bounced when its anchoring harpoons failed to deploy and a thruster designed to hold the probe to the surface did not fire. After bouncing off the surface twice, ''Philae'' achieved the first-ever "soft" (nondestructive) landing on a comet nucleus, although the lander's final, uncontrolled touchdown left it in a non-optimal location and orientation. Despite the landing problems, the probe's instruments obtained the first images from a comet's surface. Several of the instruments on ''Philae'' made the first direct analysis of a comet, sending back data that would be analysed to determine the composition of the surface. In October 2020, scientific journal ''Nature'' published an article which re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Comet
A comet is an icy, small Solar System body that, when passing close to the Sun, warms and begins to release gases, a process that is called outgassing. This produces a visible atmosphere or coma, and sometimes also a tail. These phenomena are due to the effects of solar radiation and the solar wind acting upon the nucleus of the comet. Comet nuclei range from a few hundred meters to tens of kilometers across and are composed of loose collections of ice, dust, and small rocky particles. The coma may be up to 15 times Earth's diameter, while the tail may stretch beyond one astronomical unit. If sufficiently bright, a comet may be seen from Earth without the aid of a telescope and may subtend an arc of 30° (60 Moons) across the sky. Comets have been observed and recorded since ancient times by many cultures and religions. Comets usually have highly eccentric elliptical orbits, and they have a wide range of orbital periods, ranging from several years to potentially several mill ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lander (spacecraft)
A lander is a spacecraft that descends towards, comes to rest on, the surface of an astronomical body. In contrast to an impact probe, which makes a hard landing that damages or destroys the probe upon reaching the surface, a lander makes a soft landing after which the probe remains functional. For bodies with atmospheres, the landing occurs after atmospheric entry. In these cases, landers may employ parachutes to slow them down enough to maintain a low terminal velocity. In some cases, small landing rockets will be fired just before impact in order to reduce the lander's velocity. Landing may be accomplished by controlled descent and set down on landing gear, with the possible addition of a post-landing attachment mechanism (such as the mechanism used by ''Philae'') for celestial bodies with low gravity. Some missions (for example, Luna 9 and Mars Pathfinder) used inflatable airbags to cushion the lander's impact rather than utilizing more traditional landing gear. When a hi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cologne
Cologne ( ; german: Köln ; ksh, Kölle ) is the largest city of the German western States of Germany, state of North Rhine-Westphalia (NRW) and the List of cities in Germany by population, fourth-most populous city of Germany with 1.1 million inhabitants in the city proper and 3.6 million people in the Cologne Bonn Region, urban region. Centered on the left bank of the Rhine, left (west) bank of the Rhine, Cologne is about southeast of NRW's state capital Düsseldorf and northwest of Bonn, the former capital of West Germany. The city's medieval Catholic Cologne Cathedral (), the third-tallest church and tallest cathedral in the world, constructed to house the Shrine of the Three Kings, is a globally recognized landmark and one of the most visited sights and pilgrimage destinations in Europe. The cityscape is further shaped by the Twelve Romanesque churches of Cologne, and Cologne is famous for Eau de Cologne, that has been produced in the city since 1709, and "col ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Egyptian Hieroglyphs
Egyptian hieroglyphs (, ) were the formal writing system used in Ancient Egypt, used for writing the Egyptian language. Hieroglyphs combined logographic, syllabic and alphabetic elements, with some 1,000 distinct characters.There were about 1,000 graphemes in the Old Kingdom period, reduced to around 750 to 850 in the classical language of the Middle Kingdom, but inflated to the order of some 5,000 signs in the Ptolemaic period. Antonio Loprieno, ''Ancient Egyptian: A Linguistic Introduction'' (Cambridge: Cambridge UP, 1995), p. 12. Cursive hieroglyphs were used for religious literature on papyrus and wood. The later hieratic and demotic Egyptian scripts were derived from hieroglyphic writing, as was the Proto-Sinaitic script that later evolved into the Phoenician alphabet. Through the Phoenician alphabet's major child systems (the Greek and Aramaic scripts), the Egyptian hieroglyphic script is ancestral to the majority of scripts in modern use, most prominently the Latin and Cyr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rosetta Stone
The Rosetta Stone is a stele composed of granodiorite inscribed with three versions of a Rosetta Stone decree, decree issued in Memphis, Egypt, in 196 BC during the Ptolemaic dynasty on behalf of King Ptolemy V Epiphanes. The top and middle texts are in Egyptian language, Ancient Egyptian using Egyptian hieroglyphs, hieroglyphic and Demotic (Egyptian), Demotic scripts respectively, while the bottom is in Ancient Greek. The decree has only minor differences between the three versions, making the Rosetta Stone key to decipherment of ancient Egyptian scripts, deciphering the Egyptian scripts. The stone was carved during the Hellenistic period and is believed to have originally been displayed within a temple, possibly at Sais, Egypt, Sais. It was probably moved in late antiquity or during the Mamluk Sultanate (Cairo), Mamluk period, and was eventually used as building material in the construction of Fort Julien near the town of Rashid (Rosetta) in the Nile Delta. It was found there ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Philae Obelisk
The Philae obelisk is one of a pair of twin obelisks erected at Philae in Upper Egypt in the second century BC. It was discovered by William John Bankes in 1815, who had it brought to Kingston Lacy in Dorset, England, where it still stands today. The Greek and Egyptian hieroglyphic inscriptions on the obelisk played a role in the decipherment of ancient Egyptian hieroglyphs. Description The obelisk was originally one of a pair that stood at the east pylon of the temple of Isis at Philae. The other obelisk of the pair was broken into pieces in antiquity. The surviving obelisk consists of a long shaft, topped by a pyramidion and a rectangular base. The bottom of the shaft is a modern restoration. Including the modern base, it stands roughly seven metres tall. There are two inscriptions: a hieroglyphic text on the shaft and a Greek text on the base. An additional painted Greek text on the base was observed in 1815, but has now been lost due to weathering. The inscriptions are publi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Safe Mode (spacecraft)
Safe mode is an operating mode of a modern unmanned spacecraft during which all non-essential systems are shut down and only essential functions such as thermal management, radio reception and attitude control are active. Safe mode is entered automatically upon the detection of a predefined operating condition or event that may indicate loss of control or damage to the spacecraft. Usually the trigger event is a system failure or detection of operating conditions considered dangerously out of the normal range. Cosmic rays penetrating spacecraft electrical systems can create false signals or commands and thus cause a trigger event. The central processor electronics are especially prone to such events. Another trigger is the lack of a received command within a given time window. Lack of received commands can be caused by hardware failures or mis-programming of the spacecraft, as in the case of the Viking 1 lander. The process of entering safe mode, sometimes referred to as ''safing'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nature (journal)
''Nature'' is a British weekly scientific journal founded and based in London, England. As a multidisciplinary publication, ''Nature'' features peer-reviewed research from a variety of academic disciplines, mainly in science and technology. It has core editorial offices across the United States, continental Europe, and Asia under the international scientific publishing company Springer Nature. ''Nature'' was one of the world's most cited scientific journals by the Science Edition of the 2019 ''Journal Citation Reports'' (with an ascribed impact factor of 42.778), making it one of the world's most-read and most prestigious academic journals. , it claimed an online readership of about three million unique readers per month. Founded in autumn 1869, ''Nature'' was first circulated by Norman Lockyer and Alexander Macmillan as a public forum for scientific innovations. The mid-20th century facilitated an editorial expansion for the journal; ''Nature'' redoubled its efforts in exp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Independent
''The Independent'' is a British online newspaper. It was established in 1986 as a national morning printed paper. Nicknamed the ''Indy'', it began as a broadsheet and changed to tabloid format in 2003. The last printed edition was published on Saturday 26 March 2016, leaving only the online edition. The newspaper was controlled by Tony O'Reilly's Irish Independent News & Media from 1997 until it was sold to the Russian oligarch and former KGB Officer Alexander Lebedev in 2010. In 2017, Sultan Muhammad Abuljadayel bought a 30% stake in it. The daily edition was named National Newspaper of the Year at the 2004 British Press Awards. The website and mobile app had a combined monthly reach of 19,826,000 in 2021. History 1986 to 1990 Launched in 1986, the first issue of ''The Independent'' was published on 7 October in broadsheet format.Dennis Griffiths (ed.) ''The Encyclopedia of the British Press, 1422–1992'', London & Basingstoke: Macmillan, 1992, p. 330 It was produc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Comet Nucleus
The nucleus is the solid, central part of a comet, once termed a ''dirty snowball'' or an ''icy dirtball''. A cometary nucleus is composed of Rock (geology), rock, dust, and frozen gases. When heated by the Sun, the gases Sublimation (physics), sublime and produce an atmosphere surrounding the nucleus known as the Coma (cometary), coma. The force exerted on the coma by the Sun's radiation pressure and solar wind cause an enormous tail to form, which points away from the Sun. A typical comet nucleus has an Albedo#Astronomical albedo, albedo of 0.04. This is blacker than coal, and may be caused by a covering of dust. Results from the Rosetta (spacecraft), ''Rosetta'' and Philae (spacecraft), ''Philae'' spacecraft show that the nucleus of 67P/Churyumov–Gerasimenko has no magnetic field, which suggests that magnetism may not have played a role in the early formation of planetesimals. Further, the Rosetta (spacecraft)#Instruments, ALICE spectrograph on ''Rosetta'' determined that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NASA
The National Aeronautics and Space Administration (NASA ) is an independent agency of the US federal government responsible for the civil space program, aeronautics research, and space research. NASA was established in 1958, succeeding the National Advisory Committee for Aeronautics (NACA), to give the U.S. space development effort a distinctly civilian orientation, emphasizing peaceful applications in space science. NASA has since led most American space exploration, including Project Mercury, Project Gemini, the 1968-1972 Apollo Moon landing missions, the Skylab space station, and the Space Shuttle. NASA supports the International Space Station and oversees the development of the Orion spacecraft and the Space Launch System for the crewed lunar Artemis program, Commercial Crew spacecraft, and the planned Lunar Gateway space station. The agency is also responsible for the Launch Services Program, which provides oversight of launch operations and countdown management f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Comet
A comet is an icy, small Solar System body that, when passing close to the Sun, warms and begins to release gases, a process that is called outgassing. This produces a visible atmosphere or coma, and sometimes also a tail. These phenomena are due to the effects of solar radiation and the solar wind acting upon the nucleus of the comet. Comet nuclei range from a few hundred meters to tens of kilometers across and are composed of loose collections of ice, dust, and small rocky particles. The coma may be up to 15 times Earth's diameter, while the tail may stretch beyond one astronomical unit. If sufficiently bright, a comet may be seen from Earth without the aid of a telescope and may subtend an arc of 30° (60 Moons) across the sky. Comets have been observed and recorded since ancient times by many cultures and religions. Comets usually have highly eccentric elliptical orbits, and they have a wide range of orbital periods, ranging from several years to potentially several mill ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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